Illuminant for incandescent lamps



(No Model.) A. DE LODYGUINE.

ILLUMINANT FOR INGANDESOENT LAMPfil.

" No.575,002 Patented-Jan.12,1897.

* Wlli Him/v5.1

To (all whom, it may concern.-

' UNITE STAT S- PA TF ow ALEXANDER DE LODYGUINE, or PIT'ISBURG, rnnusr vAmA 1 .IL-LUMINANT FOR mcmosscsn'r' LAMPS.

srnorrrcnrrou forming part of Letters wa no, 575,boa, datd-Iannary 12, 897. 1 I v Q I Application filed January 4,1893. Serial lie- 457,221. (No specimens.)

Be it known that I, ALEXANDER DE Lem?- GUINE, acitizen of Russia, residing in the city of Pittsburg, in the county of Allegheny and- State of Iennsylvanim have invented a new and useful Improvement in Illuminants. for Incandescent Lamps and Methods of Making the Same, (Case No. 535,) of which the following is a specification.

" My invention relates to the constructionof' incandescent conductors or burners for incandescent electric lamps. 6' In the com merr cial lamps now in use filaments of carbon are invariably employed as the illuminant. In the early experiments with incandescent l'ampsit was attempted to employ metals having high fusing-points. ,Platinum in particular was experimented with, but it was found that for various reasons a commercial lamp could not be made with anylmetal filament produced by anyof the processes then known.

-In practice it is necessary that the illuminant should be capable of enduring a very high temperature, especially because the en' ergy consumed per candle-power decreases very rapidly with increase of temperature.

It was found that platinum fused ata temperature lowerithan that which is required to produce a commercially-efficient lamp; llyletal possesses inherent qualities which vrende'r' it more-desirable material for forming an illuminant than carbon. Thus theloss of heat by radiation at a given temperature is 'found to vary considerably with the character of the surface. A carbon filament loses a large amount of heat byradiatiom; and this detracts materially from the amount of light emitted.

A metallic illuminant aifordsa surface of .a

much brighter and better character for light radiation and a less opportunity for heat radiation than is usually obtainable from a carbon filament. For this reason a metallic illu-- minant has advantages over a carbon filament.

I have discovered that the following metals possess all the essential qualities for forming a practical, commercially eflicient metallic "illuminant for incandescent electric lamps,

namely, molybdenum and tungsten, rhodium and iridium, ruthenium and osmium, and chromium, and I have also discoveredm'eans whereby they may be formed into an attenuated thread-like'w'ire in ail-economical and successful manner. All these metals areinfusible at such temperatures as are necessary to render them brilliantly incandescent,and'

are very eflieientas' light-producing mediums.

They are, however, almost absolutely non 2: ductile, and are extremely hard and brittle.

They therefore cannot bedrawn out into wires in the manner employed in operating upon ductilemetals, While there are other metals known to science having fusing points suificiently high for use in "this art,'and processes are knownwhereby they may be separated from their compounds, yet those above enumerated'are found particularly desirable for the purposes of my invention, although such other metals, when prepared in the manner herein described by me,-w,i ll fall within the scope of this pate1it.' 1 v I My, moth expressed in general terms, is'as follows:

I-first form an exceedingly fine'wire' or" thread-like base out-of any desired conducting material, but preferably out of'platin'um. This wire should have in ordinary cases a did of illuminant-manufa'oturing,

ameter not greater than one thousandth of] w an inch and usuallyless than this. Such wiresare made from'platinum, gold, and sil-; ver without great difiiculty. They may also be made from other metals and even from carbon. The diameter of this base is prefer- :ably insignificantas compared to that of the completed illuminant, although in some cases it maybe desirable to employ a'base of appreciablo size. 'I n.'tliis specification I shall ture and not as a portion of itself. As un derstood by me and as the term-is used in this specification the illuminant is bf annu- Upon this fillet I .lar cross-section and is of a-single homogeneous metallic structure as opposed to acomposite structure. In other words, the fillet is nota portion of the illuminant, is not necessary to its permanence, and may, indeed, be removed without detriment to the illuminant or incandescent and light-giving body.

I have illustrated my illuminant and the relation of the fillet thereto in the accompan ying' drawings, wherein.

Figure 1 is a longitudinal centralsection of a preferred form of lamp provided withmy illuminant, shown therein in section and Fig.

2is a sectional view, on a larger scale, of my illuminant and filletbroken off at and yy.

The lamp-1, preferably provided with a stop .butany conducting substance may be e'mployed which is capable of bearing 'the temperature needed for. the decomposing process as usually practiced by me, although where the; galvano-plastic process isjemployed' this I refractory character is not necessarily pres 2 ent.

5 The-firtt step in my methodof manufacture is to give to my conducting-fillet the form to be imparted to the illuminant. The next step is-to deposit upon the surface of this pro 3o viously formed fillet thebody whic h is to' serve as an incandescent orilluminant. Numero'us processes inay be followed in pursuing this method of manufacture, and I desire N it to be understood that in pointing out one 3 5 process or class of processes I do not desire to I limit myself to anything-lessthan the broad method of forming metallic illuminants as set "out, in my method-claims following this description; 1 4 l o, before stated, the metals which] have 'used in preference to others thus far may be divided into .four groups with relation to the various processes applicable to each in carrying' out my method of manufacture. 5 The first group given by me above is molybdenum and; tungsten or Wolfram. There exis't a number of processes whereby the method of deposition of a filament, made of one of these materials upon a cond ucting-fil-let may be carried out. The two principal ones whereby I have been successful with metals of this group are as follows: If a chlorid or chlorate of a member of this group be volatilized' by heating and the resulting vapor min- I 5 5 gled with hydrogen, the mixed gases will deposit metallic molybdenumvor tungsten, as the casemay be, upon the fillet when the same is heated in the mixture by the electric current or otherwise. Again, if the chlorid 6c of these metals be fused and employed as an electrolyte, the fillet being immersed in the same as one of the poles, the metal will be galvanically deposited thereon.

The second group, rhodium and iridium,

6-5 admits of the following treatment: If solutions of oxids, oxysal-ts, or haloid salts of this group are treated as electrolytes and the fillet is placed at one of the poles, less soluble ox.- ids or salts may be deposited upon the fillet, and in some cases even the metal itself will be deposited.

metal in some cases by simply heating away fromai r, and' in others by the action of hydrogen upon the heated oxid. This heating is preferably accomplished by means of the electric current. I

The third group, ruthenium and osmium, admits of the following treatment:- When acids having this group as a radical are heated they form a vapor; I

- drogen with this vapor and heating the fillet, preferably by electricity, in the resulting mixture the metal is deposited upon the fillet, thus producing the desired filamen t. Again, these acids in a'fused condition are'found to deposit, metal upon a filletplaced-"at one of the-moles, and deposition; may also be accomplished from solutions of the same acids.

5 The above processes have. been set forth thusbriefiy in order to give some idea of the lVhen 'oxids' or s'altsare de-- posited, however, they may be reduced to Upon mixing hynumber of processes whereby my method may.

be'carried'out; but itisthe' treatment of the fourth group, whichI propose to describe more at length, to which my more specific claims will be directed. In this group there is only one metal which I have practically employed hitherto for making incandescent illuminants, and that is chromium. In d e-i positing this metal uponthe fillet I may make a solution of a salt thereof and deposit chromium oxid upon the fillet therefrom galvan-- ically; but I have hitherto found the following' methods more certain and economical: The oxychlorid of chromium CrCl 2Cr0 or (H0 01 is a dark-red liquid fumingstrongly at ordinary temperatures. -If'the conducting-fillet while surrounded by the fumes of ,this compound he heated by a current, de-

composition of the oxychlorid will result and the following reaction will take place: 2(Jr0 Cl =Or O +2Cl +Ol As thisdecomposition takes place :only in immediate proximity to' the fillet the chromium oxid thus produced is deposited 'upon the fillet in an even'layer. This layer is black and is made up of extremely minute crystals. Y

As above stated, molybdenum, tungsten, ruthenium, and osmium may be deposited in metallic form from vapors of theircompounds mingled with hydrogen-{but with the oxychlorid of chromium this process should not be followed, as the mixture of oxychlorid and hydrogen explodes on mere contact. In order, therefore, to obtain a layer'of metallic chro- 'mium, the fillet, covered with a chromic oxid resulting from the above-described treatment, is heated in an atmosphere of hydrogen. It

is highly desirable that this hydrogen should ,be chemically pure" and as dry as possible.

The usual chemical means for securing these 7 ,e'mooa drogen the following reduction takes place:

ried E with thehydrogen, which I prefer to use 'as astream, and the metallic chromiumis g "3 left upon the fillet. By repeated incasings and reductions an illuminant of proper crosssection is built up. Of course I might leave non-ductile metal and containing a fillet of difierent material.. r

3. An illuminant for electric lamps com-' posed of an incandescing. body of practically non-ductile metal and containing a fillet of ductile metal.

1. 4. An illuminant for electric lamps composed of an incandescingbody of practically non-ductile and infusible metal and containing a fillet of platinum. i

'5. -An illuminant for electric lamps composed'of an incandescing body of chromium and containing a fillet of conducting matethe fillet in the oxychlorid long enough to. build up an oxid illuminant of suflicient crossa a section at one operation, and then reduce the whole at once; but in this case, as the oxid isa non-conductor, the fillet would be the only source of heat, and a much thicker illuminant .'would take a very long time to reduce. The

5 thickness of'the oxid illuminant would be a' rial. g 1 great objection where the heating was carried 6. An illuminant for electric lamps comonbymeans otherthanbythe electric current. posed of an incandescing body of chromium Another method whereby chromiummay'be and containinga fillet of platinum. deposited upon the fillet is as follows: I first '7'. The method of making illuminantsfor o I dip the fillet into the liquid oxychlorid. After electric'lampswhich consists in infpartin g to 3o 1. An incandescing illuminant'for thus' dippingjthe fillet I subject the same- 1 while heated, preferably by theelectric cur-.

rent, totheaction of moistairor of steam.

The.'rea( \on then. taking place is as follows:

J ero,c1 H,0=2Hc1+oro,.-; The resulting hydroc loric acid is carriedoff and the chromicacid-is left ou -the fillet. The same coat-.

' ing of chromic acid maybe obtained by passing a mixture of moist air and the fumes of g o oxychlorid of chromiumover the heated fillet.

Upon subjecting the'fillet thus incased with Gro to the action of pure hydrogen the fol lowing double reaction takes place: r0,'+ Y6H=3H,O+Cr O -,5 the fillet and is of a green color, having the The' Cr O remains on same composition as the black oxid above described, but being an allotropic form of the same. The second half of the reaction is as follows: 2Cr,O +6H=4Cr+3H O. :These't'wo .oreactions take placetogether and in theory successively; The whole operation ofdipping and reduction should of course'be repeated as often as is necessary to produce the desired cios's-sectionof illuminant. The layerof oxid 5 may also be obtained,-if"desired,' by dipping the fillet into a solution of 050 and drying thesame.

'I fully appreciate the factthat other; processesthan-those above mentioned. and detailed maybe employed in carrying out my method of making metallic illuminants, and lilo not limit myself to any oneor all of those enumerated herein. I look upon it as a novel method of making metallic illuminants. to

3 5 build them up around a fillet having no per-.

manent function, but merely serying as a I support during manufacture, much as a mold supports a casting.

I claim as my'invention. I

electric lamps composed of'an incandescing'rnet'allic body and containing a conducting-fillet of different material, substantially as described. 2. An illuminant for electric lamps coma conducting-fillet the shape desired, depositiug thereon a metallic oxid and subjecting a heating-current through the. filletand sub- .jecting the heated fillet to the'action of a metallic oxid and of hydrogen gas; I

9. Aprocess of making illu'minants for electric lamps which consists in-impartiug'the desired shape tofa conducting-fillet, passing "a heating-current through the fillet in an atmosphere of vaporizedchromium oxid and subsequently heating the resulting illuminant in an atmosphere of hydrogen.

electric lamps which consists in imparting the shape desired to a conducting-fillet, passing a heating-current through the fillet in an-atmosphereof chlorochromic acid and subsequently heatingth'e resulting illuminant in an atmosphere of hydrogen.

11. The method of making illuminants for electric lamps which consists in bending a platinum fillet to the shape desired, passing a heating-current through said fillet in an atpassing a heating-current through the result ing illuminant in an atmosphere of hydrogen.

' 1 12. The method of making illuminants for. electric lamps which consists in imparting the shape desired to a conducting-fillet, dipping said fillet into liquid chlorochromic acid, and subjecting thedipped fillet to the action of heat, moist air and hydrogen.

. 10. The method of makingilluminants fer Inosp'here of chlorochromic' acid and then In testimony whereofI have'hereunto sub scribed my name this 10th day of December, A. D. 1892. Y v

g I A. DE'LODYGUINE.

Witnesses:

JAMES WM. SMITH,

lIARoLn S. M'AOKAYE, 

